When you or your Scrabble opponent has so many vowels on their rack, they can't make a word on the board, or the only word that can be made is going to score very low. Complaining about having too many vowels and getting irritable reign over swapping a vowel tile and skipping a turn.

player #1: your turn.
player #2: dude, I can't even make a word, I have too many vowels.
player #1: swap some tiles, then.
player #2: no, it's ok. I will just make this two letter word and get a crappy point score.
player #1: sounds like you are suffering from Irritable Vowel Syndrome.